Heat 1 tablespoon oil in a large skillet over medium-high heat. Add sliced onions and peppers, season with salt and pepper, and cook for 6-8 minutes until soft and caramelized. Remove from pan and set aside.
Add remaining tablespoon of oil to the same skillet. Increase heat to high and add sliced steak in a single layer. Season with salt and pepper and let cook without stirring for 2 minutes.
Flip the meat and cook for another 2 minutes until browned. Break up meat with a spatula and cook for an additional minute.
Return the onions and peppers to the skillet and mix everything together. Divide the mixture into 4 sections in the pan and top each section with 2 slices of provolone. Cover the pan and let cheese melt for about 1 minute.
Meanwhile, butter and toast the hoagie rolls in another pan or under the broiler until golden.
Scoop each cheesy meat section into a toasted roll and serve immediately. Have napkins ready—these are deliciously messy!